CHE 2100 Spring 2012

General Organic & Biological Chemistry ReviewV

A general note: Short answer questions are just that, short. Writing a paragraph filled with every term you can remember from class won’t improve your answer— just answer clearly, succinctly, and in your own words.

1. Why is it impractical to make amides by reacting a carboxylic acid with an amine?

2. Draw the enantiomer of the following molecule:

3. What requirements must a carbon atom have to be chiral?

4. How many stereocenters are present in the following compound?

5. How many stereoisomers are possible for the following triglyceride (Include all types of stereoisomerism)?

6. Which of the following pairs of stereoisomers are related as enantiomers?

7. Progesterone, which is present in humans as a single stereoisomer, has six stereocenters. Human progesterone is one of how many possible stereoisomers for this structure?

8. Dextrorotatary compounds rotate plane-polarized light in which direction?

9. The drugs Prilosec and Nexium both contain the same active ingredient. Nexium contains a single enantiomer but Prilosec is a racemic mixture. Which drug will be more effective if you receive a 20 mg dose of each? How much more effective?

10. How many different triose sugars exist?

11. How many chiral carbons are present in the straight chain form of Glucose? What about the cyclic ring form?

12. If the following structure  or  D-glucose? Circle the feature(s) that determine this designation.

13. The two simplest sugars are glyceraldehyde and dihydroxyacetone. Dihydroxyacetone does not rotate the angle of plane polarized light. Why?

13. A glycosidic bond occurs when ______on a sugar reacts with ______on another sugar.

14. Draw the reaction which results in trans fatty acids in processed foods.

Upcoming material:

15. An 1,4 glycosidic bond is found in what types of molecule in plants?

16. In your own words, explain why people with type AB bloodgroup are often called “universal acceptors”.

17. Grass-eating animals require symbiotic relationships with gut bacteria. In molecular terms, what can these bacteria do that the animal cannot do itself?

18. Name three roles of lipids.

19. What are the components of a triglyceride? What type of functional group links these components?

20. Stearic acid is very common in both plant and animal tissues, while oleic acid is much more common in plant tissues. How does oleic acid differ from stearic acid?

21. Describe the structure of phosphatidylcholine. What class of lipid is it, and what role does it serve in the body?

22. If the weather outside is cold, why does your body’s usage of cholesterol increase?